Abstract
A filter module with a perforated inner tube (20) and a concentric, perforated outer tube (22), forming an interposed annular gap for a filter membrane (10) pleated into folds. The membrane folds (11, . . . ) are of different fold types with differing fold heights, extend from a respective fold edge (111, . . . ) resting against the outer tube towards the inner tube to the respective fold tip (114, . . . ) and are arranged along the circumference of the annular gap as groups of folds (11, . . . ) of different types. Each group has a mating fold (15) which extends from a mating fold edge (151) resting against the inner tube towards the outer tube to the mating fold tip (154. The height of the mating fold is no more than the difference between the width of the annular gap and the height of the fold type with the shortest height of the same group.
Claims
1. A filter module comprising: a perforated inner tube and a perforated outer tube concentrically surrounding the inner tube, wherein the inner tube and the outer tube form an annular gap there between; and a filter membrane which is pleated into folds arranged in the annular gap, wherein the folds of the filter membrane are subdivided into plural fold types of mutually differing fold height, extend from respective edges of the folds, which abut against the outer tube, towards the inner tube to respective tips of the folds, and are arranged along a circumference of the annular gap as groups of folds of different fold types, and wherein each group of folds has a counter-fold that extends from edges of the counter-fold, which abut against the inner tube towards the outer tube, to a respective tip of the counter-fold, and that has a fold height that is less than or equal to a difference between a width of the annular gap and the fold height of the fold type that has a smallest fold height within the group of folds.
2. The filter module as claimed in claim 1, wherein the folds are subdivided into two fold types of mutually differing fold height to form a fold and counter-fold arrangement.
3. The filter module as claimed in claim 2, wherein the two fold types of mutually differing fold height consist of a relatively large, first fold height and a relatively small, second fold height.
4. The filter module as claimed in claim 2, wherein, in a circumferential direction of the annular gap, the fold and counter-fold arrangement within each group of folds has a sequence as follows: a fold of a first fold type, a fold of a second fold type, the counter-fold, and a further fold of the second fold type.
5. The filter module as claimed in claim 2, wherein, in a circumferential direction of the annular gap, the fold and counter-fold arrangement within each group of folds has a sequence as follows: a fold of a second fold type, a fold of a first fold type, the counter-fold, and a further fold of the first type.
6. The filter module as claimed in claim 2, wherein, in a circumferential direction of the annular gap, the fold and counter-fold arrangement within each group of folds has a sequence as follows: a fold of a second fold type, a fold of a first fold type, and the counter-fold.
7. The filter module as claimed in claim 1, wherein the folds are subdivided into three fold types of mutually differing fold height to form a fold and counter-fold arrangement.
8. The filter module as claimed in claim 7, wherein the three fold types of mutually differing fold height consist of a largest, first fold height, a medium, second fold height and a smallest, third fold height.
9. The filter module as claimed in claim 7, wherein, in a circumferential direction of the annular gap, the fold and counter-fold arrangement within each group of folds has a sequence as follows: a fold of a first fold type, the counter-fold, a fold of a third fold type, and a fold of a second fold type.
10. The filter module as claimed in claim 7, wherein, in a circumferential direction of the annular gap, the fold and counter-fold arrangement within each group of folds has a sequence as follows: a fold of a second fold type, a fold of a third fold type, the counter-fold, a further fold of the third fold type, and a fold of a first fold type.
11. The filter module as claimed in claim 7, wherein, in a circumferential direction of the annular gap, the fold and counter-fold arrangement within each group of folds has a sequence as follows: a fold of a second fold type, a fold of a third fold type, a fold of a first fold type, a further fold of the third fold type, and the counter-fold.
12. The filter module as claimed in claim 1, wherein the folds are subdivided into four fold types of mutually differing fold height to form a fold and counter-fold arrangement.
13. The filter module as claimed in claim 12, wherein the four fold types of mutually differing fold height consist of a largest, first fold height, a relatively large, medium, second fold height, a relatively small, medium, third fold height and a smallest, fourth fold height.
14. The filter module as claimed in claim 12, wherein, in a circumferential direction of the annular gap, the fold and counter-fold arrangement within each group of folds has a sequence as follows: a fold of a second fold type, a fold of a third fold type, a fold of a first fold type, a fold of a fourth fold type, and the counter-fold.
15. The filter module as claimed in claim 1, wherein all of the counter-folds equal to one another in height.
16. The filter module as claimed in claim 1, wherein the fold height of the fold type having a largest fold height in the group of folds is less than or equal to the width of the annular gap.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In the figures:
[0032] FIG. 1 shows a schematic representation of the fold pattern within a group in a first embodiment of the 2-fold-type family,
[0033] FIG. 2 shows a schematic representation of the fold pattern within a group in a second embodiment of the 2-fold-type family,
[0034] FIG. 3 shows a schematic representation of the fold pattern within a group in a third embodiment of the 2-fold-type family,
[0035] FIG. 4 shows a schematic representation of the fold pattern within a group in a fourth embodiment of the 2-fold-type family,
[0036] FIG. 5 shows a schematic representation of the fold pattern within a group in a first embodiment of the 3-fold-type family,
[0037] FIG. 5A shows a schematic representation of a modification of the embodiment in FIG. 5,
[0038] FIG. 6 shows a schematic representation of the fold pattern within a group in a second embodiment of the 3-fold-type family,
[0039] FIG. 7 shows a schematic representation of the fold pattern within a group in a third embodiment of the 3-fold-type family,
[0040] FIG. 8 shows a schematic representation of the fold pattern within a group in an embodiment of the 4-fold-type family,
[0041] FIG. 9 shows a realistic representation of a detail of a pleated membrane which is folded according to the scheme in FIG. 1,
[0042] FIG. 10 shows a realistic representation of a detail of a pleated membrane which is folded according to the scheme in FIG. 8,
[0043] FIG. 11 shows a realistic representation of a detail of a pleated membrane which is folded according to the scheme in FIG. 4, and
[0044] FIG. 12 shows a realistic representation of a detail of a pleated membrane which is folded according to the scheme in FIG. 5A, and
[0045] FIG. 13 shows a realistic representation of a detail of a pleated membrane which is folded according to the scheme in FIG. 7.
DETAILED DESCRIPTION
[0046] Identical reference signs in the figures indicate identical or analogous elements.
[0047] FIGS. 1 to 8 show, in a schematic representation, fold patterns within different embodiments of in each case one fold group. For the formation of the entire pleated membrane, such groups or combinations of groups are positioned one after the other in a preferably periodic sequence. FIGS. 9 to 12 show, in a realistic representation, details of the entire pleated membrane in the compressed final fitting position, inserted into an annular gap between two tubes (inner and outer tube, not represented separately) of a filter module according to the invention, thereof.
[0048] The schematic representations in FIGS. 1 to 8 are all to be read as follows: What is represented in each case is a filter membrane 10 between an inner tube 20 and an outer tube 22, which are represented in developed, that is to say straightened, form in FIGS. 1 to 8. The central circle 24 which runs centrally, that is to say with an equal spacing, between the inner tube 20 and the outer tube 22, is represented by a dot-dashed line. The reference lines represented in dashed form mark the tip circles, that is to say they serve for illustrating the radial position of the fold or counter-fold tips, and are denoted by Roman numerals I, II, III, IV, according to the respective fold type, or by G, as a reference to the counter-fold. Here, 11 denotes a fold of a first fold type, 12 denotes a fold of a second fold type, 13 denotes a fold of a third fold type, 14 denotes a fold of a fourth fold type and 15 denotes a counter-fold. Particular regions of the folds 11, 12, 13, 14 and counter-folds 15 are denoted by three-digit Arabic numerals, whose first two digits in each case denote the fold 11, 12, 13, 14 or counter-fold 15 in question and whose third digit specifies the particular region. In this case, xx1 means (counter-)fold opening, xx2 means (counter-)fold edge, xx3 means (counter-)fold flank and xx4 means (counter-)fold tip. The bridge sections between a counter-fold 15 and a closest neighboring fold 11, 12, 13, 14 thereof are denoted by 16.
[0049] All the folds 11, 12, 13, 14 extend from the outer tube 22 in the direction of the inner tube 20 into the annular gap formed between the two tubes. The counter-folds 15 extend in the opposite direction, from the inner tube 20 toward the outer tube 22 into the annular gap. All the folds 11, 12, 13, 14 begin, according to the definition used here, at their respective fold opening 111, 121, 131, 141, which is formed between two fold edges 112, 122, 132, 142 abutting against the outer tube 22, run along their fold flanks 113, 123, 133, 143 and end at their respective fold tip 114, 124, 134, 144. The counter-folds 15 begin, according to the definition used here, at their respective counter-fold opening 151, which is formed between two counter-fold edges 152 abutting against the inner tube 20, run along their counter-fold flanks 153 and end at their respective counter-fold tip 154.
[0050] FIG. 1 shows a preferred embodiment of the 2-fold-type family. The filter membrane 10 has folds of two types, specifically long folds 11 of a first fold type and short folds 12 of a second fold type. The counter-folds 15 are each flanked by two short folds 12. The counter-fold edges 152 are connected to the circumferentially closest neighboring fold edges 122 via the bridge sections 16. The dimensioning of the fold heights is selected such that the fold tips 114 of the long folds 11 project significantly beyond the central circle 24, but not as far as the inner tube 20. The fold tips 124 of the short folds 12 do not project all the way to the central circle 24. The counter-fold tips 154, by contrast, project slightly beyond the central circle 24, but are situated radially spaced apart from the fold tips 124 of the short folds 12.
[0051] FIG. 9 presents a photograph of a pleated membrane in a fitted position in a filter module according to the invention, which pleated membrane is folded according to the folding scheme in FIG. 1.
[0052] The folding scheme in FIG. 2 differs from that in FIG. 1 in four features: firstly, the fold tips 114 of the long folds 11 project as far as the inner tube 20; secondly, the fold tips 124 of the short folds 12 project beyond the central circle 24; thirdly, the counter-fold tips 154 do not project up to the central circle 24; and fourthly, no radial spacing is left between the fold tips 124 of the short folds 12 and the counter-fold tips 154.
[0053] FIG. 3 shows a further embodiment of the 2-fold-type family. Here, the counter-folds 15 are each flanked by two long folds 11. The fold tips 124 of the short folds 12 end at the same radius as the counter-fold tips 154. Otherwise, reference may be made to the explanation for FIG. 1.
[0054] FIG. 4 shows a further embodiment of the 2-fold-type family. This differs from the embodiment according to FIG. 3 by the omission of a second long fold 11 per group (on the right-hand side next to the respective counter-fold 15). This variant maximizes, within the 2-fold-type family, the number of counter-folds 15 provided in the entire pleated membrane, since the total number of folds 11, 12 per group is minimized to two. FIG. 11 shows a photograph of a corresponding pleated membrane in a fitted position.
[0055] FIG. 5 shows a preferred embodiment of the 3-fold-type family. The filter membrane 10 has folds of three types, specifically long folds 11 of a first fold type, medium-length folds 12 of a second fold type and short folds 13 of a third fold type. The counter-folds 15 are each flanked by a long fold 11 and a short fold 13. The counter-fold edges 152 are connected to the circumferentially closest neighboring fold edges 112 and 132 via the bridge sections 16. The dimensioning of the fold heights is selected such that the fold tips 124 of the medium-length folds 12 project significantly beyond the central circle 24, but not as far as the inner tube 20. The fold tips 114 of the long folds 11 project as far as the inner tube 20, against which they abut. The fold tips 134 of the short folds 13 do not project all the way to the central circle 24. The counter-fold tips 154, by contrast, project slightly beyond the central circle 24, but are situated radially spaced apart from the fold tips 134 of the short folds 13. This variant maximizes, within the 3-fold-type family, the number of counter-folds 15 provided in the entire pleated membrane, since the total number of folds 11, 12, 13 per group is minimized to three. FIG. 5A and FIG. 12 show a very similar folding scheme, in which, however, a further short fold 13 is situated between each long fold 11 and the closest neighboring medium-length fold 12 thereof.
[0056] The folding scheme in FIG. 6 differs from that in FIG. 5 substantially in that the counter-folds 15 are each flanked by two short folds 13, which each have a neighboring medium-length fold 12 and a neighboring long fold 11. The dimensioning of the fold heights corresponds to that in FIG. 5, with the exception that the counter-fold tips 154 and the fold tips 134 of the short folds 13 are situated at the same radius.
[0057] In the embodiment in FIG. 7, which is likewise assigned to the 3-fold-type family, an even finer graduation is achieved in that even the long folds 11 do not project as far as the inner tube 20. The medium-length folds 12 project only as far as the central circle 24. The counter-folds 15 are each flanked by a short fold 13 and a medium-length fold 12. Otherwise, reference may be made to what has been said above with regard to FIG. 6. FIG. 13 shows a photograph of corresponding pleated material in a fitted position.
[0058] FIG. 8 shows a preferred embodiment of the 4-fold-type family. The filter membrane 10 has folds of four types, specifically long folds 11 of a first fold type, relatively long medium-length folds 12 of a second fold type, relatively short medium-length folds 13 of a third fold type and short folds 14 of a fourth fold type. This embodiment differs from the embodiment in FIG. 7 substantially by a splitting of the short folds 13 there into the short folds 14 here and the relatively short medium-length folds 13. The counter-folds 15 are each flanked by a short fold 14 and a relatively long medium-length fold 12. The counter-fold edges 152 are connected to the circumferentially closest neighboring fold edges 142 and 122 via the bridge sections 16. The dimensioning of the fold heights is selected such that the fold tips 124 of the relatively long medium-length folds 12 project as far as the central circle 24. The fold tips 114 of the long folds 11 project significantly beyond the central circle 24, but not as far as the inner tube 20. The counter-fold tips 154 project likewise beyond the central circle 24, are situated at the same radius as the fold tips 134 of the relatively short medium-length folds 13 and are radially spaced apart from the fold tips 144 of the short folds 14. This variant maximizes, within the 4-fold-type family, the number of counter-folds 15 provided in the entire pleated membrane, since the total number of folds 11, 12, 13, 14 per group is minimized to four. FIG. 10 shows a photograph of this folding scheme.
[0059] The embodiments discussed in the specific description and shown in the figures represent merely illustrative exemplary embodiments of the present invention. In the light of the disclosure here, a person skilled in the art is offered a broad spectrum of possible variants. In particular, the fold patterns presented in FIGS. 1 to 8 may also be realized in an inverted and/or cyclically permutated manner. Also, for the formation of an entire pleated membrane, the combination of mutually differing fold patterns is feasible.
LIST OF REFERENCE SIGNS
[0060] 10 Filter membrane [0061] 11 Folds of first type, long folds [0062] 111 Fold opening of 11 [0063] 112 Fold edge of 11 [0064] 113 Fold flank of 11 [0065] 114 Fold tip of 11 [0066] 12 Folds of second type [0067] 121 Fold opening of 12 [0068] 122 Fold edge of 12 [0069] 123 Fold flank of 12 [0070] 124 Fold tip of 12 [0071] 13 Folds of third type [0072] 131 Fold opening of 13 [0073] 132 Fold edge of 13 [0074] 133 Fold flank of 13 [0075] 134 Fold tip of 13 [0076] 14 Folds of fourth type [0077] 141 Fold opening of 14 [0078] 142 Fold edge of 14 [0079] 143 Fold flank of 14 [0080] 144 Fold tip of 14 [0081] 15 Counter-fold [0082] 151 Counter-fold opening of 15 [0083] 152 Counter-fold edge of 15 [0084] 153 Counter-fold flank of 15 [0085] 154 Counter-fold tip of 15 [0086] 16 Bridge section [0087] 20 Inner tube [0088] 22 Outer tube [0089] 24 Central circle [0090] I, II, III, IV Tip circles of 114, 124, 134, 144 [0091] G Tip circle of 154
